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Topic: exhale - Open Source USAC encoder (Read 302293 times) previous topic - next topic
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Re: exhale - Open Source USAC encoder

Reply #575
Thanks Chris. Reading exhale's license has a link to Via Licensing and their FAQ states:

Quote from: Via Licensing
Who must sign a license?
An AAC patent license is needed by manufacturers or developers of end-user encoder and/or decoder products.


Re: exhale - Open Source USAC encoder

Reply #577
What I said regarding the patents was if they were using exhale.

You can search for any licensee on the Via website (https://www.via-corp.com/licensing/aac/licensees/) and buy from whoever sells you the encoder. If I can spare you the trouble, I bought the Exhale encoder included in one of its products from Poikosoft to avoid any legal problems. Find it here:
https://www.poikosoft.com/music-converter


 

Re: exhale - Open Source USAC encoder

Reply #580
develop_ipf_0b14fafc_finish_1.1.2_release
random search noise in [a..g] modes

Re: exhale - Open Source USAC encoder

Reply #581
this "bug" can be traced from the very appearance of the [a..g] modes (exhale-develop_v1.1a_2020-11-10_1259070c)

Re: exhale - Open Source USAC encoder

Reply #582
What you're describing sounds like what guruboolez first reported here. See also this post and the following comment by kode54. Nothing I can do about that in exhale (unfortunately... I actually tried improving on that issue with commit 44f6b15b to develop_ipf, but it doesn't make a difference).

Chris
If I don't reply to your reply, it means I agree with you.

Re: exhale - Open Source USAC encoder

Reply #583
ok. not a "bug" - "feature". it does not affect normal listening. sorry for the "panic".

Re: exhale - Open Source USAC encoder

Reply #584
xHE-AAC is audibly non-transparent even at mode 9 in my ABX tests. Does this codec only aim for good quality at low bitrates, or are there plans to make it better for high bitrate transparency in the future?

Re: exhale - Open Source USAC encoder

Reply #585
@jdimsa: Don't you think that if you make that bold statement, you should also give an explanation of what is wrong, and since you did some ABX tests, also attach them?

Else, it doesn't help at all to improve anything that could need improvement.

Re: exhale - Open Source USAC encoder

Reply #586
Does this codec only aim for good quality at low bitrates, or are there plans to make it better for high bitrate transparency in the future?
That depends on whether the issue you hear is the result of, well, insufficiently sophisticated encoding, or a bug. From previous test reports, transparency at CVBR mode 9 (~192 kbit/s) is not guaranteed, as the following estimate (which I posted previously) shows.

Notice how the estimation curve and the actual data value around 192 kbit/s are below 5.0 (5 = acoustic transparency even in ABX tests).

If there's a sample on which you hear obvious artifacts even at mode 9, yes, please link to it here and mention the time range where you hear the artifact, so I can take a look at it.

Chris
If I don't reply to your reply, it means I agree with you.

Re: exhale - Open Source USAC encoder

Reply #587
:



If there's a sample on which you hear obvious artifacts even at mode 9, yes, please link to it here and mention the time range where you hear the artifact, so I can take a look at it.

Chris

I wouldn't say obvious artifacts; mode 9 quality is very solid. But I can definitely detect the typical shortcomings of insufficient lossy encoding such as the shimmering sound from a cymbal not being perfectly reproduced, which Apple Q109 does manage.

Re: exhale - Open Source USAC encoder

Reply #588
@jdimsa: ... and since you did some ABX tests, also attach them?

Else, it doesn't help at all to improve anything that could need improvement.

:



If there's a sample on which you hear obvious artifacts even at mode 9, yes, please link to it here and mention the time range where you hear the artifact, so I can take a look at it.

Chris

I wouldn't say obvious artifacts; mode 9 quality is very solid. But I can definitely detect the typical shortcomings of insufficient lossy encoding such as the shimmering sound from a cymbal not being perfectly reproduced, which Apple Q109 does manage.

Please post an ABX log and also supply Chris with the audio track that you've identified the issue with. Chris is here and willing to investigate if there is an issue and potentially fix it (if appropriate).


Re: exhale - Open Source USAC encoder

Reply #590
Again, I don't believe what I'm hearing are obvious artifacts due to a bug, it's just the extremely subtle difference caused by insufficiently sophisticated encoding. Nonetheless, I went back and did more testing, and found that I could pick mode 8 very easily (8/8 in only 3 minutes). I did 16 runs for mode 9 to be more thorough, and got 13/16 (although I kinda rushed through mode 9 as well, only spending 10 minutes total). I'm not sure if 13/16 is a high enough score to be a statistically significant sign of actually having spotted the difference (when you consider the base level score you are likely to get from the chance of picking the right one by accident), or if I just got lucky, however I'm fairly confident I was able to hear a more subtle version of the same artifact(s) that were immediately apparent in mode 8.

The main difference I notice is at the 900 millisecond mark in the sample, where the lyric "just" has one of those MP3-style artifacts on it (not sure how to describe). The cymbals that come half a second later also sound different, and "cut" or "roll off" sooner in the xHE-AAC version.

Re: exhale - Open Source USAC encoder

Reply #591
Thanks for the files. Technically, the mode 9.m4a looks perfectly fine. Could it be that your high-frequency hearing (above ~17 kHz with normal music, not pure tones) is exceptionally good? And to rule out any playback related issues: which decoder did you use? Foobar2000 with kode54's packet decoder?

Getting 13/16 on mode 9 is actually not that unusual, I'd say. Igor's 2020 test showed already that exhale scores with an average MOS of about 4.9 out of 5, see also the image I posted above.

Chris
If I don't reply to your reply, it means I agree with you.

Re: exhale - Open Source USAC encoder

Reply #592
 :o :-[
I believe I'm out for helping on this...

I can only hear the difference in the "just" word that you mention at preset 1 (67kbps) and by paying attention (I didn't even realize at first, although once detected, I can focus on it).
preset 5 (128kbps) is already difficult for me to distinguish.

Tried a-g on this sample and, to me, even preset a (40kbps) sounds fantastic (not transparent, obviously, but good, and that's without resampling to 32Khz which is supposed to improve the quality). I can only discern differences in stereo imaging in the cymbals, and probably some preecho, which is considerably reduced at c (64kbps). And, of course, the difference in the "just" word.


Re: exhale - Open Source USAC encoder

Reply #594
Thanks, JAZ, for having a second listen. And of course to jdimsa for reporting this. I'm sorry, but there's not much I can do here. Meanwhile,

exhale 1.1.2 has been released.

Changes since exhale 1.1.1 from last month:
  • further improved file interoperability and seekability with some playback software
  • exhaleLib: write all frames in «stss» data as immediate playout frames (issue #15)

Compared to NetRanger's last RC, there is only a slight stabilization for strongly out-of-phase input (which should occur very rarely, if at all) at CVBR modes 5 and above.

Chris
If I don't reply to your reply, it means I agree with you.


Re: exhale - Open Source USAC encoder

Reply #596
Excellent. I haven't actually tried ABX comparisons, but find both the 3 and c modes to be not-annoying and therefore passablefor compact distribution or otherwise just casual listening.

FYI RhythmBox on Linux is a passable player for these, if the local GStreamer happens to have FDK support enabled, like on Arch. No seeking support whatsoever yet, but at least they play without much fiddling!

Here, have some macOS dual arch (x86 64+arm64) binaries, signed and notarized:

https://f.losno.co/exhale-v1.1.2-0-g7d2b818.zip

Re: exhale - Open Source USAC encoder

Reply #597
exhale v1.1.2-7 Release-d2b818e Intel compiles are now on Rarewares. ;)

Re: exhale - Open Source USAC encoder

Reply #598
-7? But it's 0 commits past the 1.1.2 tag. The 7 is the first digit of the commit hash.

Re: exhale - Open Source USAC encoder

Reply #599
Oops!! It's correct on Rarewares, just a 'typo' on the post above! It should, of course, read:

exhale v1.1.2-Release-7d2b818e Intel compiles are now on Rarewares.

Apologies for any confusion caused. ;)